1. Technical Field
The present disclosure relates to a light-emitting apparatus having a photoluminescent layer.
2. Description of the Related Art
Some optical devices, such as lighting fixtures, displays, and projectors, have high directionality, and others have low directionality. Photoluminescent materials, such as those used for fluorescent lamps and white light-emitting diodes (LEDs), emit light in all directions. Thus, these devices theoretically have low directionality or wide-angle light distribution characteristics. In various uses, however, light-emitting apparatuses are required to emit strong light in a desired direction or to have narrow-angle light distribution characteristics. In order to emit strong light in a particular direction, general light-emitting apparatuses include an optical component, such as a reflector or lens, together with a photoluminescent material. For example, Japanese Unexamined Patent Application Publication No. 2010-231941 discloses an illumination system including a light distributor and an auxiliary reflector to provide sufficient directionality.